/*
 *  Copyright (c) 2011 Ondrej Dusek
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without modification,
 *  are permitted provided that the following conditions are met:
 *  Redistributions of source code must retain the above copyright notice, this list
 *  of conditions and the following disclaimer.
 *  Redistributions in binary form must reproduce the above copyright notice, this
 *  list of conditions and the following disclaimer in the documentation and/or other
 *  materials provided with the distribution.
 *  Neither the name of Ondrej Dusek nor the names of their contributors may be
 *  used to endorse or promote products derived from this software without specific
 *  prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 *  OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 *  OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package en_deep.mlprocess.computation.wekaclassifier;

import en_deep.mlprocess.utils.Pair;
import java.util.List;
import weka.core.Instances;

/**
 * A linear sequence taking all instances in the data set one-by-one.
 * @author Ondrej Dusek
 */
public class LinearSequence implements Sequence {

    /* DATA */

    /** The data set over which the sequence is to iterate */
    private Instances data;

    /** The current position in the data set */
    private int curPos;


    /* METHODS */

    /**
     * Initialize this {@link LinearSequence}
     * @param data the data set over which this sequence should iterate
     */
    public LinearSequence(Instances data){
        this.data = data;
        this.curPos = -1;
    }


    @Override
    public int getNextInstance() {

        this.curPos++;

        if (this.curPos >= this.data.numInstances()){
            return -1;
        }
        return this.curPos;
    }

    @Override
    public void setCurrentClass(double value) {

        this.data.get(this.curPos).setClassValue(value);
    }

    /**
     * Do not require a rewrite of any neighborhood information.
     * @return null
     */
    @Override
    public List<Pair<Integer, double[]>> getCurNeighborhood() {
        return null;
    }

}
